Effects of leg dominance on performance of ballet turns (pirouettes) by experienced and novice dancers

Turns (pirouettes) are an important movement in ballet and may be affected by “lateral bias”. This study investigated physiological differences exhibited by experienced and novice dancers, respectively, when performing pirouette with dominant and non-dominant leg supports, respectively. Thirteen novice and 13 experienced dancers performed turns on dominant or non-dominant legs. The maximum ankle plantarflexion, knee extension and hip extension were measured during the single-leg support phase. The inclination angle of rotation axis is the angle between instantaneous rotation axis and global vertical axis in the early single-leg support phase. Both groups exhibited a greater hip extension, knee extension, and ankle plantarflexion when performing a turn on the non-dominant leg. For experienced dancers, the inclination angle of rotation axis during the pre-swing phase was generally smaller for dominant leg support than non-dominant leg. However, no significant difference was found in inclination angle of rotation axis of novice dancers. For experienced dancers, an improved performance is obtained when using the dominant leg for support. By contrast, for novice dancers, the performance is independent of choice of support leg. The significant lateral bias in experienced dancers indicates the possible influence of training. That is, repetitive rehearsal on the preferred leg strengthens the impact of side dominance in experienced dancers.     

爵士舞运动对女大学生身体形态与素质的影响

通过4周的运动干预,动态观察爵士舞运动对200名女大学生身体形态和身体素质的影响。结果表明:爵士舞运动前、后的体重、力量素质、灵敏素质和柔韧素质均得到了有效的改善。提示,长期坚持爵士舞练习对女大学生身体形态、身体素质的改善和提高效果显著。     

高水平武术套路运动员比赛成绩影响因素分析

采用文献资料法、录像分析和数理统计等研究方法,对高水平武术套路运动员比赛成绩进行分析。结果显示：运动员的竞争非常激烈,小的失误将左右比赛的胜负;运动员之间的竞争主要在动作难度和动作质量,但不同项目不同性别存在差别;演练水平得分存在较大的发展空间。     

高校体育舞蹈教学现状及对策研究

通过对广东省部分高校体育舞蹈课程教学情况的调查，探讨体育舞蹈教学中存在的问题，建议体育舞蹈教师应该积极参与科研和体育舞蹈情报的搜集，注重理论与技术并进，加强训练学和生理生化知识在教学中的运用。     

Prediction of habitual physical activity level and weight status from fundamental movement skill level

Abstract

Fundamental movement skills (FMS) have been assessed in children in order to investigate the issues of the low proportion of children who meet physical activity (PA) guidelines and rising levels of obesity. The aim of this research was to identify whether previous or current FMS level is a better predictor of PA levels and weight status in children. In January 2012 (year 1), 281 children were recruited from one primary school in the West Midlands, UK. Children performed eight FMS three times, which were videoed and assessed using a subjective checklist. Sprint speed and jump height were measured objectively. Height and mass were measured to calculate the body mass index to determine the weight status. Skinfold calliper readings were used to calculate body fat percentage. One year later, in January 2013, all these tests were repeated on the same children, with the additional collection of PA data via the use of pedometers. Following multiple linear regression, it was identified that prior mastery in FMS was a better predictor of current PA, whereas current FMS was a better predictor of current weight status. Overall, FMS mastery is needed in childhood to be able to participate in PA and maintain a healthy weight status.     

Learning a coordination skill: interactive effects of instruction and feedback

Information prior to and during the acquisition of a continuous bimanual task was manipulated. Participants practiced a difficult coordination pattern, which produced circular shapes on the computer, when they moved their arms correctly. Four groups were examined, which differed in the type and amount of information provided. Either limb or circle feedback was provided in the presence or absence of instructions detailing how to move the limbs. Circle feedback facilitated learning relative to the limb feedback in which the explicit displacements of the limbs was displayed. Under circle feedback conditions, instructions hindered acquisition. Little instructional effects were observed under limb feedback conditions, despite the prediction that instructions would benefit learning when the feedback was more compatible. Findings are discussed in relation to the complexity of the feedback and processing demands.     

山东省高校体育舞蹈专业办学现状及发展对策

运用文献资料法、问卷调查法、专家访谈法、数理统计法,从山东省高校体育舞蹈专业办学的现状出发,调查师资、场地、舞蹈课程以及男女生比例,分析目前存在的问题,给出相应的建议,希望能为山东省体育舞蹈专业的发展提供参考。     

右脑运动潜能开发与排球扣球技能习得关系的实验研究

以体育院系排球选修班学生为研究对象,采用分组“单盲”教学实验,从心理、生理学的角度出发,探讨在排球扣球技术教学中,实施以挖掘学生内在运动潜能和改善人体右脑运动调节功能为目的的双侧肢体同步交叉技能学习的教学策略,是否有利于双侧肢体技能的交叉迁移,影响优势侧（右侧）肢体运动技能的习得进程。实验结果表明,通过上述教学策略的运用可以促进右侧手运动技能的掌握进程,对学生的正面扣球技术技评和达标成绩都产生了积极的影响。     

Effect of skill level on cardiorespiratory and metabolic responses during Tai Chi training

Abstract

Nowadays, Tai chi chuan (TCC) is practiced by millions worldwide with a range of skill levels. However, the effect of skill level on physiological response to TCC performance has yet to be clarified. In this study, physiological parameters during practicing simplified 24-form TCC were investigated and compared in 10 young high-level (HL) male TCC athletes and 10 ordinary-level (OL) male TCC practitioners with similar age and body size. Significantly higher energy expenditure, heart rate, oxygen uptake and tidal volume were found in HL group than OL group during TCC performance. The respiratory frequency and exhalation time were similar between the two groups during practicing TC; however, significantly less inhalation time was found in HL group (1.02±0.2 s) than OL group (1.12±0.28 s). Our results suggested that skill level may have considerable impact on metabolic and cardiorespiratory responses to TCC performance. TCC practitioners with different skill levels may practice TCC in different ways, which was supposed to lead to distinguishable response between the two groups.     

Bilateral inter-arm coordination in freestyle swimming: effect of skill level and swimming speed

The aim of this study was to examine the influence of level of skill and swimming speed on inter-limb coordination of freestyle swimming movements. Five elite (2 males, 3 females; age 18.9+/-1.0 years, height 1.71+/-0.04 m, body mass 62.1+/-7.0 kg) and seven novice (age 22.0+/-2.0 years, height 1.77+/-0.04 m, body mass 74.8+/-9.0 kg) swimmers swam a sprint and a self-paced 25 m freestyle trial. The swimming trials were recorded by four digital cameras operating at 50 Hz. The digitized frames underwent a three-dimensional direct linear transformation to yield the three-dimensional endpoint kinematic trajectories. The spatio-temporal relationship between the upper limbs was quantified by means of the peak amplitude and time lag of the cross-correlation function between the right and left arm's endpoint trajectories. A strong anti-phase coupling between the two arms, as confirmed by peak amplitudes greater than 0.8, was noted for both groups and swimming speeds. Significantly higher (P<0.05) peak amplitudes were observed for the sprint compared with self-paced swimming. No significant differences in the strength of inter-limb coupling were noted between the elite and novice swimmers (P>0.05). Time lags were very close to 0 ms and did not differ between groups or swimming speeds. We conclude that in freestyle swimming, the intrinsic anti-phase (180 degrees phase difference) inter-limb relationship is strongly preserved despite the physically powerful environmental influence of the water and this "preferred" pattern is not affected by level of skill. In contrast, increasing movement speed results in stronger inter-limb coupling that is closer to the anti-phase inter-limb relationship.     

Bilateral inter-arm coordination in freestyle swimming: Effect of skill level and swimming speed

The aim of this study was to examine the influence of level of skill and swimming speed on inter-limb coordination of freestyle swimming movements. Five elite (2 males, 3 females; age 18.9?±?1.0 years, height 1.71?±?0.04?m, body mass 62.1?±?7.0?kg) and seven novice (age 22.0?±?2.0 years, height 1.77?±?0.04?m, body mass 74.8?±?9.0?kg) swimmers swam a sprint and a self-paced 25?m freestyle trial. The swimming trials were recorded by four digital cameras operating at 50 Hz. The digitized frames underwent a three-dimensional direct linear transformation to yield the three-dimensional endpoint kinematic trajectories. The spatio-temporal relationship between the upper limbs was quantified by means of the peak amplitude and time lag of the cross-correlation function between the right and left arm's endpoint trajectories. A strong anti-phase coupling between the two arms, as confirmed by peak amplitudes greater than 0.8, was noted for both groups and swimming speeds. Significantly higher (P <?0.05) peak amplitudes were observed for the sprint compared with self-paced swimming. No significant differences in the strength of inter-limb coupling were noted between the elite and novice swimmers (P >?0.05). Time lags were very close to 0?ms and did not differ between groups or swimming speeds. We conclude that in freestyle swimming, the intrinsic anti-phase (180° phase difference) inter-limb relationship is strongly preserved despite the physically powerful environmental influence of the water and this “preferred” pattern is not affected by level of skill. In contrast, increasing movement speed results in stronger inter-limb coupling that is closer to the anti-phase inter-limb relationship.     

Underwater and surface strategies of 200 m world level swimmers

Pacing strategies of elite swimmers have been consistently characterised from the average lap velocities. In the present study, we examined the racing strategies of 200 m world class-level swimmers with regard to their underwater and surface lap components. The finals and semi-finals of the 200 m races at the 2013 World Swimming Championships (Barcelona, Spain) were analysed by an innovative image-processing system (InThePool® 2.0). Free swimming velocities of elite swimmers typically decreased throughout the 200 m race laps (?0.12 m · s^–1, 95% CI ?0.11 to ?0.14 m · s^–1, P = 0.001, η² = 0.81), whereas underwater velocities, which were faster than free swimming, were not meaningfully affected by the race progress (0.02 m · s^–1, ?0.01 to 0.04 m · s^–1, P = 0.01, η² = 0.04). When swimming underwater, elite swimmers typically travelled less distance (?0.66 m, ?0.83 to ?0.49 m, P = 0.001, η² = 0.34) from the first to the third turn of the race, although underwater distances were maintained on the backstroke and butterfly races. These strategies allowed swimmers to maintain their average velocity in the last lap despite a decrease in the free swimming velocity. Elite coaches and swimmers are advised to model their racing strategies by considering both underwater and surface race components.     

感、知觉能力对艺术体操集体项目运动员技能水平的影响

运用文献资料、图像解析等研究方法,从感、知觉角度出发,结合艺术体操集体项目特点论述了部分感、知觉能力对艺术体操集体项目运动员身体动作与器械技术完成的影响,从中找出感、知觉与运动员技能水平的关系,为艺术体操集体项目的发展提供借鉴。     

Age-related differences in vision and proprioception in a lower limb interceptive task: the effects of skill level and practice

This study examined age-related differences in the role of visual proprioception during a lower limb interceptive action and how this varies as a function of skill and practice. In Experiment 1, skilled and less-skilled 8-, 10-, and 12-year-old boys controlled a soccer ball using their preferred foot under full vision and when sight of the effector was occluded. With the exception of the high-skilled 12-year-olds and low-skilled 8-year-olds, participants showed a decrement in peformance when denied access to visual proprioception. In Experiment 2, the effect of practicing under different informational constraints was examined for 12 year-old boys. Children performed varying amounts of practice under full vision, or in a condition where sight of the foot was occluded, before being transferred to the alternative viewing condition. Participants who practiced under occluded viewing conditions showed greater relative improvement in performance over practice and transfer sessions compared with a full vision control group. Some support is provided for the manipulation of visual informational constraints as an effective pedagogical approach to motor learning.     

中国传统养生功法的发展理念与策略

在中国申奥的成功、全民健身计划纲要的进一步深入以及中国医疗制度的改革这一利好的局面下，全国人民的健康意识得到了进一步的加强，我们应及时抓住这个机遇，采取正确的发展理念与策略，努力推广古老而具有旺盛生命力的传统养生功法，发挥其独特的健身功能。     

我国高校高水平运动队发展的若干问题与发展对策

针对社会主义市场经济条件下我国普通高校高水平运动队发展中存在的经费投入不足、目标与现实脱节、运动竞赛次数太少、项目发展无序、制约高校办队的竞训体制、缺乏规划和训练质量评价系、科研潜力不能有效转化等问题进行了深入研究.提出了改革运作机制、引入市场机制、试办俱乐部制的高校办队模式、合理规划运动项目发展布局、积极拓宽招生渠道、缩短竞赛周期、改革参赛办法、建立训练质量评价体系和定期评价制度、加强与体育院校和体育科研单位的合作等积极的应对措施,旨在保证我国普通高校竞技体育的可持续发展.     

优秀女子套路运动员刀棍技能水平的现状研究--兼对十运会预决赛刀术棍术评分内容的相关分析

对十运会女子刀棍全能项目预、决赛中评分内容的相关分析表明:难度动作在一定程度上影响动作质量;难度技术是影响最后得分的主导因素;女子刀棍运动员技能发挥的稳定性尚待提高。     

女子摔跤技战术特征探索及对伦敦奥运备战的启示

通过对2006、2007世界锦标赛及2004、2008年奥运会女子摔跤比赛现场观摩和录像采集,运用数理统计方法,从世界强国、不同级别、顶尖队员三个维度对技战术特征进行分析。结果表明:虽在北京奥运会上中国队、日本队、加拿大队技战术综合表现居各队之首,每分钟技战术攻防综合能力(Pts/min)为0.62分、0.59分和0.29分,但对比两届奥运会发现,世界各国差距正逐渐缩小,技战术呈现攻防能力均衡化趋势;通过对不同级别技战术攻防能力分析,发现中小级别的比赛攻防节奏快、回合多,大级别比赛中高级技术和大幅度动作运用较多,技战术运用呈现男性化、力量化特点;从顶尖队员的角度来比较,中国队王娇和日本队吉田沙宝里攻防能力均衡,其每分钟得分能力分别为1.76和1.97分。并从对手信息、体能保障、制胜技术和模拟实战四个方面提出我国女子摔跤技战术能力训练策略,为备战伦敦奥运会提供科学参考依据。     

Coincidence timing of a tennis stroke: effects of age, skill level, gender, stimulus velocity, and attention demand

Participants (N = 162, ages 10-15 years) performed a tennis stroke in a coincidence-timing task. Major results were: (a) performance improved mainly between the ages of 10-13 years; (b) skill differences were reflected by variable error (VE); (c) boys were lower than girls for VE and absolute error; (d) high stimulus velocity was related to low VE and late responding. Results concerning response organization favored explanations based on ecological perspectives rather than information processingperspectives. However, it is premature to disregard the potential role of programming. The view is supported that a continuous process of coupling perceptual and motor responses coordinates control of response timing. These cognitive processes appear to be: (a) refined with practice; (b) sensitive to differences in age, skill, and gender; and (c) adaptable to changes in environmental demands.